2010 Toyota Prius
Mileage
217,945
Service Date
2/4/2022
Services Performed
- Inspected vehicle for customer concern. Found check engine light on, and engine running rough upon gas motor engagement. Connected scan tool and checked for error codes. Found 3 codes stored and current in ECU. Codes are P0300 (Random Cylinder Misfire), P0302 (Cylinder 2 Misfire), and P0304 (Cylinder 4 Misfire). Checked live data and confirmed misfires are present when vehicle starts up. Numbered ignition coils and swapped coils 1&3 with coils 2&4 respectively. Cleared codes and test started vehicle. Error codes returned for cylinder 2 and 4 misfires. Removed spark plugs to check condition. Plugs look to be newer, but have some staining on insulation around electrode. Found excess pressure within cooling system when removing coolant reservoir cap. Performed combustion gas test on cooling system. Test failed, fluid changed color indicating combustion gasses are entering the cooling system. Recommend removal of cylinder head for inspection/rebuild and replacement of cylinder head gasket.
- Removed engine covers and splash shields. Removed intake piping, air filter housing, power distribution box, and underhood reservoirs for access. Drained cooling system. Disconnected radiator hoses and fans. Removed ignition coils and upper engine wiring. Removed intake manifold and throttle body. Disconnected exhaust from cylinder head. Removed timing covers and valve cover from engine. Disconnected timing chain and removed timing components. Found guides worn. Recommend replacement of timing chain and components during reassembly of engine. Removed cylinder head from engine. Removed cams and rockers from cylinder head. While head was being refurbished, cleaned pistons and engine deck to prep for new head gasket installation. Inspected removed components. Found intake manifold has clogged egr ports and is full of carbon buildup. Recommend new intake manifold. Installed rebuild cylinder head with new head gasket, head bolts, and washers. Torqued head bolts to factory specification. Installed cam followers, cam bridge, and camshafts. Installed new timing guides, chains, and tensioner. Installed timing cover with new gasket material. Installed valve cover with new gasket. Reinstalled exhaust manifold with new gasket. Transferred throttle body and fuel injection components to new intake manifold and installed with new gaskets. Installed remaining engine accessories and covers with new gaskets where available. Installed new spark plugs. Drained oil after completing engine assembly. Refilled engine with fresh oil and installed new oil filter. Reconnected coolant hoses and reinstalled underhood fluid reservoirs. Filled engine cooling system and bled. Reinstalled power distribution, air intake components, and covers. Cycled vehicle on, ok. Started engine and checked for any leaks or running issues. Engine running normally and no leaks present. Cleared error code history and test drove vehicle. Check engine light did not return, no rough running or misfires felt. Rescanned vehicle. No error codes stored nor pending.
- Disassemble and Inspect Head Hot Tank Cleaning Pressure Test Cylinder Head – OK Glass Bead Blast Head and Valves Check Valve Guide Clearance – OK 3 Angle Cut Valve Seats Regrind Valves Surface Cylinder Head .003" Assemble Valves and Springs Vacuum Test After Assembly – OK
Caitlin M. gave our service a 5 star review on 2/5/2022
